Blower



R. RosNER.

BLOWER.

Y I APPLICATION FILED IAN. 23| 1920. 1,346,796. Patented July 13, 1920.,

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BLOWER. APPLICATION FILED AN. 23.1920.

Patented July 13, 1920.

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UNITED `s'mfr-Es PATENT OFFICE.

RUDOLF RosNER, or CHICAGO, ILLINOIS.

, BLOWER.

Specification of Letters Patent. Patented J uly 13, 1920.

Application led .Tanuary 23, 1920. Serial No. 353,467.

A thereby especially adapted for certain thera-n peutic uses. It consists in the elements and features of construction shown and described as indicated in the claims.

.In the drawings Figure 1 is a' vertical axial section of a ,blower embodying this invention.

Fig. 2 is a side elevation of the same with one of the case members removed showing the rotor in side view.

Fig. 3 is a detail section at the line, 3-3, on Fig. 2.

The blower shown in the drawings comprises two fixed standards, l and 2, upon and between whichv there is mounted the blower casing, comprising two similar members, 3, 3, facing each other'and making airtight junction at their periphery for inclosing the rotor, 4. The case members have each a central aperture, 3a, and they are mounted upon the standards by means of annular fillet-and-groove featuresseen at 1b, 3",`the fillets being formed on the outer faces of the case'members respectively, and the grooves upon theinner faces of the standard members respectively, so that the 'case when mounted upon and between the standards is rotatable with respect to the standards about the axis of the rotor. The rotor is journaled in the standards, or one of them,

having its axle or shaft upon which is fixed, 5, extending through the central aperture of the case member for Obtaining its journal bearing in the extended journal, 1,

' of the standard. .As illustrated in the drawings, only one of the standards is provided with a journal for the rotor. The other 4standard is provided .with an air inlet connection, 1d, co-axial with the rotor and with the central apertures of the casing. This specific cOnstructiOn,-with one air inlet and one bearing for the rotor,-is convenient for certain uses for which the blower shown is designed, but is not a characteristic of the invention herein claimed.

The detail form of the rotor is designed to overcome or avoid a defect generally discovered in blowers of this general type when they are applied to uses requiring uniform velocity\of the air current delivered, as in certain therapeutic devices and apparatus. It is known that inblowers ofcommon construction, thereresult eddies and vortices in the air movementwhich at some particular speed of the rotor, tend to cause accumulating back pressure which is relieved by spasms or instants of sudden dropping of speed, accompanied by more or less violent vibration of the' blower. These vortices and eddies I have ascertained, result from the conflict of the normal centrifugal flow f air outward along the fan blades with what may be termed knife blade blasts of air passing laterally by the fan blades or airdriving arms, which are necessarily not fitted air-tight in the casing, but run clear of the inner surfaces of the casing by a distance suflicient to insure avoidance of actual Contact and the friction which would result from such contact. The structurevof the'rotor herein shown in respect to the fan blades or air driving arms overcomes this trouble,'

by producing an air packing between the casing and the air driving arms or blades. This is done by forming these arms, 4b, with air pockets, 4;, at their opposite sides open toward-the casing walls respectively, said` pockets being also open at their inner ends, at 4d, and closed at their outer ends, so that the centrifugal action causes the air to be packed or compressed in these pockets, and also so that the air compressed in advance of the air-'driving arm, and driving or tending to drive between said arms and the walls of the casing, and tending to expand. into the pockets as it passes4 them, is thereby obstructed and halted, and additionally opposed by the air compressed in the pocket' by the centrifugal action mentioned; and thereby the knife-blade blasts mentioned are substantially prevented.

The pocket formation of the arms, 4b, is produced by making 'them each comprise i a web, 4f, in the plane of rotation, and .a

transverse flange, 4g, which constitutes the air-driving face, an end flange, 4h, and a second flange, 4j, parallel to 4g, but extending only to the edge of the central air ,inlet aperture of the casing.` I have found that l a second transverse iange at a distance back in the direction of rotation from the flanges, 4g, and 41, operates to further obstruct the knife blade air blast. This flange, 4k, 'is extended from the end flange, 4h, and delected as seen at 4m, for junction with the web, 4f. This formation results in a through-and-through aperture, 4, from side to side of the arm, 4b, which constitutes a communication between the two pockets, 40,'

at opposite sides of the arm. And this communication has an important function in equalizing the pressure in the two pockets.

That the pressure ydeveloped in thepock' ets, 4c, is very considerable, is proven by the fact that when the pockets are present the casing is sensibly bulged when the blower is in operation. at high speed, such bulging being in excess of that which is observable when the rotor is without these pockets. I have found that uniformity of the air velocity is greatly assisted by making the periphery of the air relief passage around'the ends .of the arms, 4h, helical in form as shown,

the shortest' radius of the helixbeing slightly greater than that of the rotor, and said helical periphery extending substantially 360 degrees around the axis of the rotor, so that the dischar e connection occurs substantially opposite the shortestradius.

` lI clalm 1. In a centrifugal blower, in combination with a case having a central air inlet, a rotor in the case comprising air driving arms whose width approximately spans the air cavity'of the case, and which have on their opposite sides toward the opposing walls ofl the case air pockets open toward said walls and closed at the louter ends of the arms and open at the inner ends thereof.

2. In the structure defined in claim 1 foregoing, the two pockets at opposite sides of each arm having limited air communication with each other within the area of the arm abutting on the case wall.

3. VIn, the structure defined in claim 1 foregoing, each arm having the air pockets oc-y cupying a limited portion of the area of the arm abutting the case wall, said arms being apertured through their. entire width from case wall to case wall over an area extending alongside that occupied by the pocket;

the partition between said pocket and said -through-and-through apertures being cut away fora short distance along the inner end portion of the pocket for limited communication between the pockets at said two' proximately the width of the web, and then iexed to and projected partly across y. the web toward but not reaching the forward edge flange; and a second Aflange extending transversely to the plane of the web along the rear edgethereof from the outer end to within a short distance of the junction of vthe flexed flange with the web; vwhereby there is formed in each arm two pockets upon'opposite sides thereof, and a throughand-through passage alongside said pocket, at the inner end.

, `5. In a blower, in combination with twol opposed standards, centrally apertured case walls carried by said standards respectively, and a rotor journaled in the standards, the

case wall and standards having annular illet-and-groove 'engagement with each other co-axial with the rotor, and means for holding the standards together to embrace the case members between them; one of the standards having an air inlet conduit opposite the central aperture of the adjacent case J member, and an air discharge conduit connected to the periphery of the case.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 21 day of January, 1920.

RUDOLF Rosanna. 

